Kindly get scaling done and use sequel F toothpaste and Sequel AD mouthwash twice daily for 15 days to prevent sensitivity. If you have a problem in a tooth then kindly get an X-ray done of the tooth. May be you will have to get root canal treatment done followed by a cap /crown. Brush your teeth twice daily using correct brushing technique to maintain your oral hygiene.

Hello lybrate-user, it seems to be melanin pigmentation. Which is because of excess of melanin cells (which gives colour to skin ).it does not harm .But please still visit a dentist and get a through check up done.

Kindly get an X-ray done of the tooth having pain .may be you will have to get root canal treatment done followed by a cap /crown. Brush your teeth twice daily using correct brushing technique to maintain your oral hygiene.

Thanks for the query
As you mentioned you got fillings done recently and if you are comfortable and fine and don't have any painkiller than no need for RCT.
But if you still have pain or discomfort than better go for RCT.
Sometime after filling teeth might not trouble for longer period.
So my advice to you is if it pains than go for RCT.

A root canal is a treatment to repair and save a badly damaged or infected tooth. The procedure involves removing the damaged area of the tooth (the pulp), cleaning and disinfecting it and then filling and sealing it. The common causes affecting the pulp are a cracked tooth, a deep cavity, repeated dental treatment to the tooth or trauma. The term "root canal" comes from cleaning of the canals inside the tooth's root. Millions of teeth are treated and saved each year with root canal, or endodontic, treatment. Learn more about root canal treatment and how it can relieve your tooth pain and save your smile.

The Procedure-

A root canal procedure begins with an X-ray to determine the shape of the root canals and whether the infection has spread to the adjoining bone.

A rubber sheet is then placed around the tooth to keep the area and prevent it from the saliva.

A hole is then drilled in the affected tooth, following which the decayed pulp and nerve tissues are removed.

The removal is done by using root canal files which are inserted into the hole and then used to scrape and scrub the insides of the tooth.

After the scraping, water is used to clean and flush out the debris.

After the tooth is cleaned, it is sealed after administering medications to prevent infection.

The sealing process involves filling the inner portion of the teeth by a rubber based compound and a sealer paste.

Modern endodontic treatment is very similar to having a routine filling and usually can be completed in one or two appointments, depending on the condition of your tooth and your personal circumstances. You can expect a comfortable experience during and after your appointment. Saving the natural tooth with root canal treatment has many advantages:

Efficient chewing

Normal biting force and sensation

Natural appearance

Protects other teeth from excessive wear or strain

Post-treatment:

Once the surgery is done, the tooth may become sensitive due to inflammation of the tissues for the first few days.

This pain and inflammation can be limited by pain medications such as ibuprofen.

It is advised to avoid any chewing by the affected teeth as it can slow down the repair process. You can brush and floss your teeth regularly.

In case you have a concern or query you can always consult an expert & get answers to your questions!

Whatever you did was not right ,you should have seen a dentist for your dental problem instead.
There is nothing to worry about all you have to do is visit a dentist so your condition can be evaluated and tooth in pain can be treated. The numbness and peeling skin inside your mouth will Heal within few days.